Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > alt.sys.pdp8 > #1982

Re: PDP-8 ASCII question

From Bob Eager <news0006@eager.cx>
Newsgroups alt.sys.pdp8
Subject Re: PDP-8 ASCII question
Date 2016-04-04 12:08 +0000
Message-ID <dmf3pdFs66uU6@mid.individual.net> (permalink)
References <7ac59376-b031-44ac-9601-490ec29b3ece@googlegroups.com> <ndp8ap$k9r$1@gioia.aioe.org> <c5092533-2e15-47f0-add5-c012dab736a6@googlegroups.com> <pfp9tc-bvt.ln1@news.informatik.uni-stuttgart.de> <u5u9tc-u66.ln1@sambook.reistad.name>

Show all headers | View raw


On Mon, 04 Apr 2016 13:01:50 +0200, Morten Reistad wrote:

> In article <pfp9tc-bvt.ln1@news.informatik.uni-stuttgart.de>, Christian
> Corti  <cc@corti-net.de> wrote:
>>Dylan McNamee <dylan.mcnamee@gmail.com> wrote:
>>> That is a great thread - thanks for the pointer! It seems that this is
>>> mostly an artifact of papertape and 6-bit ASCII, both
>>of which (mostly) went away after the PDP-8.
>>
>>No and no.
>>First, ASCII is seven bits (octal 0-177). Second, it has nothing to do
>>with papertape or Teletypes. DEC simply defined the parity bit to be
>>mark (i.e. always 1), since the serial interface is 8 bits fixed.
> 
> They were not alone in doing this. Prime computer also had the MSB set
> in all of their ASCII. Saving a few cents worth of hardware in the
> serial ports and/or some cycles processing them. But leading to decades
> of incompatibility.

ISTR having the same thing on a Honeywell DDP-516.

Back to alt.sys.pdp8 | Previous | NextPrevious in thread | Next in thread | Find similar


Thread

PDP-8 ASCII question dylan.mcnamee@gmail.com - 2016-04-02 11:32 -0700
  Re: PDP-8 ASCII question Rob Doyle <radioengr@gmail.com> - 2016-04-02 12:59 -0700
    Re: PDP-8 ASCII question Dylan McNamee <dylan.mcnamee@gmail.com> - 2016-04-02 14:04 -0700
      Re: PDP-8 ASCII question Christian Corti <use@reply.to> - 2016-04-04 11:41 +0200
        Re: PDP-8 ASCII question Morten Reistad <first@last.name.invalid> - 2016-04-04 13:01 +0200
          Re: PDP-8 ASCII question Bob Eager <news0006@eager.cx> - 2016-04-04 12:08 +0000
            Re: PDP-8 ASCII question Morten Reistad <first@last.name.invalid> - 2016-04-04 16:15 +0200
        Re: PDP-8 ASCII question Klemens Krause <krause@informatik.uni-stuttgart.de> - 2016-04-04 15:21 +0200
          Re: PDP-8 ASCII question Johnny Billquist <bqt@softjar.se> - 2016-04-04 17:41 +0200
            Re: PDP-8 ASCII question "Charles Richmond" <numerist@aquaporin4.com> - 2016-04-04 15:11 -0500
              Re: PDP-8 ASCII question Rich Alderson <news@alderson.users.panix.com> - 2016-04-04 20:53 -0400
                Re: PDP-8 ASCII question "Charles Richmond" <numerist@aquaporin4.com> - 2016-04-05 15:16 -0500
                Re: PDP-8 ASCII question Johnny Billquist <bqt@softjar.se> - 2016-04-06 15:49 +0200
              Re: PDP-8 ASCII question Johnny Billquist <bqt@softjar.se> - 2016-04-05 16:43 +0200
                Re: PDP-8 ASCII question Rich Alderson <news@alderson.users.panix.com> - 2016-04-05 15:15 -0400
                Re: PDP-8 ASCII question "Charles Richmond" <numerist@aquaporin4.com> - 2016-04-05 15:20 -0500
                Re: PDP-8 ASCII question Johnny Billquist <bqt@softjar.se> - 2016-04-06 15:54 +0200
                Re: PDP-8 ASCII question "Charles Richmond" <numerist@aquaporin4.com> - 2016-04-06 15:08 -0500
                Re: PDP-8 ASCII question Johnny Billquist <bqt@softjar.se> - 2016-04-07 15:50 +0200
                Re: PDP-8 ASCII question cjl <clasystems@gmail.com> - 2017-03-25 04:07 -0700
                Re: PDP-8 ASCII question Charles Richmond <numerist@aquaporin4.com> - 2017-09-29 10:27 -0500
                Re: PDP-8 ASCII question Klemens Krause <krause@informatik.uni-stuttgart.de> - 2017-10-02 18:09 +0200
                Re: PDP-8 ASCII question Charles Richmond <numerist@aquaporin4.com> - 2017-10-07 15:21 -0500
                Re: PDP-8 ASCII question Klemens Krause <krause@informatik.uni-stuttgart.de> - 2017-10-09 14:01 +0200
                Re: PDP-8 ASCII question Charles Richmond <numerist@aquaporin4.com> - 2017-10-12 23:40 -0500
                Re: PDP-8 ASCII question Klemens Krause <krause@informatik.uni-stuttgart.de> - 2017-10-16 14:38 +0200

csiph-web